As electronic technology evolves, electronic devices are widely applied in all areas. Electronic devices are not only applied in high-tech industry area such as aerospace equipment, but also applied in consumer electronic products, such as home appliances, communication devices, and medical equipment. Electro static discharge (ESD) can be seen everywhere, and ESD problem is a threat to normal operation of the equipment. It is an issue of engineer's concern that how to prevent ESD such that the device operates normally. ESD is common in daily life, especially during the manufacturing, transporting, storing and using of the electronic device. When the electrostatic is accumulated to a certain level, energy of a certain degree would be released, which causes irreversible damage to the electronic device.
In addition, in order to bear positive voltage and negative voltage, the ESD protection circuit in the art usually includes a P-type transistor (PMOS) and an N-type transistor (NMOS). However, to achieve better conducting or current diverting effect, the P-type transistor has to occupy more circuit area.